The effect of midazolam pre-medication on rocuronium-induced neuromuscular blockade.

We investigated the effect of midazolam pre-medication on rocuronium-induced neuromuscular blockade during sevoflurane anaesthesia. Twenty-two patients scheduled for elective surgery were randomly divided to receive either no pre-medication (control group) or pre-medication with 0.1 mg/kg midazolam intramuscularly (midazolam group). Anaesthesia was induced with fentanyl and propofol, and maintained with sevoflurane and nitrous oxide in oxygen. Neuromuscular responses were monitored using acceleromyography. The onset and clinical duration of action, time to recovery of first twitch of train-of-four (TOF) response to 75% of control, recovery index and time for TOF recovery to 25% and 50% were recorded. Patient-related data were similar in both groups. The parameters recorded were not significantly different between the groups. Midazolam pre-medication does not influence the time-course of action of rocuronium during sevoflurane anaesthesia.

The role of autologous blood injection on postoperative air leak at lung resections.

BACKGROUND: The effects of autologous blood injection beneath the stapling lines on postoperative air leak after lung resections, especially in emphysematous lungs, were prospectively investigated. METHODS: The study was carried out on 16 randomized patients. The mean age of the study group was 58 and the mean forced expiratory volume at one second (FEV1) at the spirometry was 2.05 L. In the control group, the mean age was 60 and the mean FEV1 was 1.97 L. All 16 cases were males and had a history of smoking. In the study group, 10-20 ml of autologous venous blood was drawn by the anesthesist and transferred to the operation team. The blood was gently injected underneath the staple line and ultimately 1 cm thickened layer of the lung was obtained. In the control group only staplers were applied. RESULTS: There was no air leak at the end of the operation at the study group, whereas additional sutures which were pledgetted with Gore-tex patches were needed at four cases at the control group. There were minimal air leaks at three cases at the control group at the postoperative period, while there was no postoperative air leak problem at the study group. Thorax tubes were removed at the 3rd and the 3.9th days at the study and the control groups, respectively. CONCLUSIONS: We believe this simple and cheap method could be used at least in some instances where additional staple reinforcement would be necessary. It may also be remembered when air leaks are encountered at suture holes after suturing the lung.

Cost-effectiveness of minimally invasive-intervention in aortofemoral revascularization.

Minimally invasive surgical procedures have become popular recently because they offer several advantages over conventional operative techniques. A person undergoing a minimally invasive procedure usually experiences less pain, is discharged earlier from hospital, returns to work sooner and has a less obtrusive post-operative scar. Excluding highly technical techniques (e.g. laparoscopic surgery), operations performed using mini-laparotomy are usually more cost-effective than conventional procedures, largely because they are less expensive to perform. Our paper investigates cost-effectiveness and other parameters relating to minimally invasive aortofemoral revascularization procedures performed at our clinic. We compared 20 similar cases, half where revascularization was undertaken using mini-laparotomy and half where conventional laparotomy was selected. From our findings we conclude that mini-laparotomy is safe and reliable for aortobifemoral bypass procedures and has several advantages over traditional techniques; namely, shorter operating time, earlier resumption of intestinal function, shorter duration of in-patient stay and reduced costs.

The effects of nimodipine on vecuronium-induced neuromuscular blockade.

Nimodipine, a calcium channel blocking drug, is used in the treatment of cerebral arterial spasm after subarachnoid haemorrhage due to bleeding from an intracranial aneurysm. The purpose of this study was to evaluate the effects of nimodipine on neuromuscular blockade after vecuronium had been given to facilitate tracheal intubation and maintenance of muscle paralysis in patients undergoing clipping of intracranial aneurysm. Twenty patients were divided into two groups: a control group (n = 10) who received no calcium channel blocking drug, and a nimodipine group (n = 10) consisting of patients treated with nimodipine at clinically used doses of 0.03 mg kg(-1) h(-1) pre- and perioperatively. Anaesthesia was induced with atropine 10 microg kg(-1), dehydrobenzperidol 5 mg, fentanyl 5 microg kg(-1), thiopental 5 mg kg(-1) and maintained with a mixture of N2O and isoflurane (0.5-1% inspired concentration) in O2, and additional doses of fentanyl 2.5 microg kg(-1). Neuromuscular responses were monitored by acceleromyograpy. The first twitch of the train-of-four response (T1) was considered as twitch height. After a stabilization period, an intubating dose of vecuronium 0.1 mg kg(-1) was administered. The onset of action, the time of first appearance of T1 and clinical duration of action were recorded. Then, maintenance doses of vecuronium 0.03 mg kg(-1) were administered twice more when T1 had recovered to 25% of control twitch height. The study ended when the recordings of the 3rd 25% T1 recovery had been obtained. There were no statistical differences in the onset time (120+/-44 s in the control group, 141+/-33 s in the nimodipine group), in the first appearance time of T1 (28+/-6 min in the control group, 30+/-8 min in the nimodipine group), and in the times for 25% recovery in T1 (41+/-11, 32+/-2, 40+/-13 min in the control group, respectively, and 44+/-16, 36+/-15, 38+/-15 min in nimodipine group, respectively) between the groups studied. The time between the injection of the intubating dose of vecuronium and the third recovery of T1-25% of control was not significantly different between the control group (113+/-34 min) and the nimodipine group (117+/-42 min). This study indicates that nimodipine does not have any significant effect on the time course of action of vecuronium including the onset time and its clinical duration of action after the initial and the two maintenance doses in these patients.

The effect of cerebral palsy on the action of vecuronium with or without anticonvulsants.

Patients with cerebral palsy who are treated with anticonvulsant medication are resistant to vecuronium. We examined the contributions to vecuronium resistance made by cerebral palsy and anticonvulsants in a study of children with cerebral palsy and a control group. The acceleromyographic responses of the following three groups of children were studied: children with cerebral palsy not taking anticonvulsant medication (n = 11); children with cerebral palsy taking anticonvulsant medication (n = 8); and a control group of children who did not have cerebral palsy and were not taking anticonvulsant treatment (n = 10). Using a standardised technique, general anaesthesia was induced and maintained with 0.5-1. 5% isoflurane in a 60/40 nitrous oxide in oxygen mixture. After a stabilisation period which was performed with supramaximal train-of-four stimuli (2 Hz every 15 s) an intubating dose of vecuronium 0.1 mgkg-1 was administered. The first twitch of the train-of-four response (T1), the onset time, the times to 25, 50, 75 and 90% recovery of T1, recovery index, and the time to 70% recovery of train-of-four ratio were recorded. Recovery times to T1 and train-of-four responses were reduced significantly in both groups of children with cerebral palsy compared with the control group. These results suggest that children with cerebral palsy display resistance to vecuronium whether or not they are taking anticonvulsant drugs.

Resistance to vecuronium in burned children.

We compared the time-course of action of vecuronium in 16 burned children undergoing excision and autograft surgery with that of ten unburned children. Standardized anaesthesia was induced with thiopentone 4-6 mg kg-1 and fentanyl 1 microgram.kg-1 and maintained with endtidal 1-1.5% isoflurane in N2O/O2. Neuromuscular responses were monitored by acceleromyography (TOF-Guard, Organon Teknika/Biometer) with supramaximal train-of-four (TOF) stimuli delivered every 15s. Vecuronium 0.1 mg kg-1 was administered intravenously. Onset was recorded as the time, in seconds, between the initial bolus of vecuronium and a decline in the first twitch of TOF (T1) to 5% of control. The times for the recovery of T1-25%, 50% and 75% of control, recovery index and the recovery of TOF 25% and 50% were recorded. Onset of action was found slower in burned patients (189 +/- 70 s) than in control (98 +/- 20 s) (P < 0.01). Recovery times of T1(25), T1(50), T1(75), TOF25 and TOF50 were significantly shorter in burned patients indicative of decreased sensitivity to vecuronium (P < 0.01).